validatecolor
Description
validates a single color value. If the color value is valid,
RGB
= validatecolor(colors
)validatecolor
returns the equivalent RGB triplet for the color. One
of the criteria validatecolor
checks is whether one or multiple colors
are specified. For this syntax, specifying more than one color is invalid, and produces an
error.
Examples
Validate Unsigned 8-Bit Color
Validate an unsigned 8-bit color value.
RGB = validatecolor(uint8([128 0 255]))
RGB = 1×3
0.5020 0 1.0000
Validate Multiple Unsigned 16-Bit Colors
Create a 2-by-3 matrix containing the unsigned 16-bit values for two colors. Then validate the colors.
c = uint16([32768 0 65535; 0 65535 0]);
RGB = validatecolor(c,'multiple')
RGB = 2×3
0.5000 0 1.0000
0 1.0000 0
Validate Color Names
Validate three color names.
RGB = validatecolor({'red','green','blue'},'multiple')
RGB = 3×3
1 0 0
0 1 0
0 0 1
Validate Hexadecimal Colors
Validate three hexadecimal color codes.
RGB = validatecolor({'#8000FF','#0F0','#FF9900'},'multiple')
RGB = 3×3
0.5020 0 1.0000
0 1.0000 0
1.0000 0.6000 0
Validate Color in Function
Define a function called plotlines
that accepts
y
as an array of y-coordinates and
linecolors
as the colors for the lines. The function creates a
colored line plot of the values in y
.
Within the function, check the validity of linecolors
by calling
the validatecolor
function. Specify the
'multiple'
option to allow users to specify one or more colors. If
the colors are invalid, validatecolor
displays an error message.
Otherwise, it returns the equivalent RGB triplet array. Next, use the size of the
RGB
array to determine the distribution of the colors among the
lines.
Save the function as plotlines.m
in a writable folder.
function plotlines(y,linecolors) % Plot colored lines. p = plot(y); % Check for valid color values RGB = validatecolor(linecolors,'multiple'); % Use RGB array in a calculation ncolors = size(RGB,1); nlines = numel(p); nupdate = min(ncolors,nlines); for n = 1:nupdate p(n).Color = RGB(n,:); end
Call the plotlines
function to plot a red, a blue, and a black
line.
plotlines([0 1 2; 1 2 3],{'red','blue','black'})
Now call the function with an invalid color value. In this case, specify a scalar
value instead of an m-by-3 array. MATLAB® displays the error returned by the validatecolor
function.
plotlines([0 1 2; 1 2 3],255)
Error using validatecolor (line 50)
Specify colors as a three-column matrix.
Error in plotlines (line 6)
RGB = validatecolor(linecolors,'multiple');
Validate Color in Argument Block of Function
Define a function called plotminmax
that accepts
y
as an array of y-coordinates and
c
as an optional color argument. The function creates a line plot
with dashed horizontal lines at the minimum and maximum values of y
.
The dashed lines are black by default, but the user can customize the color with the
c
argument.
Within the arguments
block, check the validity of
c
with the validatecolor
function. Define
'black'
as the default color so that c
can be an
optional input. Then, plot y
, and display horizontal lines at the
minimum and maximum values using the color c
.
Save the function as plotminmax.m
in a writable folder.
function plotminmax(y,c) % Plot lines with horizontal lines indicating min/max of y. arguments y {mustBeNumeric, mustBeNonempty} c {validatecolor} = 'black' end plot(y) % Add min and max lines ymin = min(y,[],'all'); ymax = max(y, [],'all'); yline(ymin,'--','Color',c) yline(ymax,'--','Color',c) end
Call the plotminmax
function with the hexadecimal color code for
red. The function plots the coordinates and displays the horizontal lines with the
specified color.
plotminmax([8.4 2.5 7 3 9.2],'#FF0000')
Call the function with an invalid color value. In this case, specify an invalid
color name. MATLAB displays the error returned by the validatecolor
function.
plotminmax([8.4 2.5 7 3 9.2],'chartreuse')
Error using plotminmax
Invalid argument at position 2. 'chartreuse' is not a valid
color specification. Valid names include: 'red', 'green',
'blue', 'cyan', 'magenta', 'yellow', 'black', and 'white'.
Valid hexadecimal color codes consist of '#' followed by three
or six hexadecimal digits.
Input Arguments
colors
— Color values
1-by-3 vector | m-by-3 matrix | character vector | cell array of character vectors | string array
Color values to validate, specified as one of the following:
1-by-3 vector of
single
ordouble
values in the range[0,1]
, where the values correspond to the intensities of the red, green, and blue components of color, respectively.1-by-3 vector of unsigned integers, where the integers correspond to the intensities of the red, green, and blue components of color, respectively.
m-by-3 matrix of
single
ordouble
values, or unsigned integers, where each row in the matrix contains the intensities of the red, green, and blue components of a color.Character vector that specifies a color name such as
'red'
, or a hexadecimal color code such as'#F92B30'
.1-D cell array of character vectors or a string array, where each element in the array is either a color name such as
'red'
, or a hexadecimal color code such as'#F92B30'
.
The following table lists the valid color names with the equivalent RGB triplets and hexadecimal color codes.
Color Name | Short Name | RGB Triplet | Hexadecimal Color Code | Appearance |
---|---|---|---|---|
"red" | "r" | [1 0 0] | "#FF0000" | |
"green" | "g" | [0 1 0] | "#00FF00" | |
"blue" | "b" | [0 0 1] | "#0000FF" | |
"cyan"
| "c" | [0 1 1] | "#00FFFF" | |
"magenta" | "m" | [1 0 1] | "#FF00FF" | |
"yellow" | "y" | [1 1 0] | "#FFFF00" | |
"black" | "k" | [0 0 0] | "#000000" | |
"white" | "w" | [1 1 1] | "#FFFFFF" |
Example: RGB = validatecolor(uint8([255 0 0]))
Example: RGB = validatecolor("#FF8800")
Data Types: single
| double
| int8
| int16
| int32
| int64
| uint8
| uint16
| uint32
| uint64
| char
| string
sz
— Size option
'one'
(default) | 'multiple'
Size option, specified as one of the following options:
'one'
— Accept one color value only. Return an error otherwise.'multiple'
— Accept zero or more color values.
Example: RGB = validatecolor(["red"
"green"],'multiple')
Output Arguments
RGB
— RGB values
RGB triplet | matrix of RGB triplets
Equivalent RGB values, returned as one RGB triplet or multiple RGB triplets in an
m-by-3 matrix. An RGB triplet is a three-element row vector whose elements specify the
intensities of the red, green, and blue components of the color. The intensities are in
the range [0,1]
. For example, [1 0 0]
is red, and
[0.5 0.5 0.5]
is a gray midtone.
Version History
Introduced in R2020b
See Also
MATLAB 명령
다음 MATLAB 명령에 해당하는 링크를 클릭했습니다.
명령을 실행하려면 MATLAB 명령 창에 입력하십시오. 웹 브라우저는 MATLAB 명령을 지원하지 않습니다.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)